ABOUT MAX10 FPGA OVERSHOOT CIRCUIT

[MartinMaa]

Hello,

I am writing to you regarding the overshoot protection circuit (circled in red in the image).
These circuits are used for one-time use only, and I also have space constraints on my PCB.

I would like to ask if it is possible to make a separate sub-board for this circuit that can be connected during programming.
The GND of the two boards will be connected together,
and the voltage of the two boards will also be set to the same as VCCIO BANK1.

Is this feasible? If so, what are the things I need to pay attention to?

Thank you for your time and consideration.

[FvM]

Hi, using protection circuits for external signals driving FPGA pins directly is generally a good idea. If you actually observe overshoot potentially degrading or even damaging FPGA IOs depends drive strength and rise time of connected circuit as well as cable length. An USB Blaster with original cable e.g. doesn't necessarily need clamping diodes. There's still a risk of ESD damage if not using appropriate protection means, in so far your separate board doesn't solve all possible problem.

I think, it's a matter of use case, in which environment programming will be performed.

[Ash_R_Intel]

Hi,

It is feasible to have the marked circuit on the separate board, provided the GND are connected and the VCCIO is sourced from the main board.

Regards

[Ash_R_Intel]

Hi,

As the query has been answered, I am setting the case to closure. However, it will still be open for the community members to comment on.

Regards